A lead vehicle may harvest or collect material (e.g., harvested crop, grain, ore, mined materials, or other material) that is loaded into a follower vehicle that follows the lead vehicle. If the lead vehicle and the follower vehicle are manned and both moving, the operators may attempt to coordinate the relative positions of the vehicles to facilitate loading of a container associated with a follower vehicle. However, it may prove extremely difficult to coordinate the relative positions of the moving vehicles with accuracy because of potential variations in the positions of each vehicle, for instance. Accordingly, there is need to coordinate automatically the speed and position of the lead vehicle and a follower vehicle.